Oxide semiconductor TFTs have advantages, such as high migration rate, good stability, and, simple manufacturing process. Oxide semiconductor materials represented by indium gallium zinc oxide (IGZO) are widely applied in the fields, such as thin-film transistor liquid crystal displays (TFT-LCDs), and active matrix organic light-emitting diode (AMOLED) panels.
Currently, the structure of the oxide semiconductor TFTs mainly includes etching barrier type, back channel etching type and coplanar type. The manufacturing process of metal oxide IGZO TFTs of back channel etching type is relatively simple, omits one photolithography process compared with the etching barrier type, and can reduce the equipment investment and improve the production efficiency, so the back channel etching type is a research hotspot recently.